title: Comparative analyses of response surface methodology and artificial neural network on medium optimization for Tetraselmis sp. FTC209 grown under mixotrophic condition.
abstract: Mixotrophic metabolism was evaluated as an option to augment the growth and lipid production of marine microalga Tetraselmis sp. FTC 209. In this study, a five-level three-factor central composite design (CCD) was implemented in order to enrich the W-30 algal growth medium. Response surface methodology (RSM) was employed to model the effect of three medium variables, that is, glucose (organic C source), NaNO3 (primary N source), and yeast extract (supplementary N, amino acids, and vitamins) on biomass concentration, X(max), and lipid yield, P(max)/X(max). RSM capability was also weighed against an artificial neural network (ANN) approach for predicting a composition that would result in maximum lipid productivity, Pr(lipid). A quadratic regression from RSM and a Levenberg-Marquardt trained ANN network composed of 10 hidden neurons eventually produced comparable results, albeit ANN formulation was observed to yield higher values of response outputs. Finalized glucose (24.05 g/L), NaNO3 (4.70 g/L), and yeast extract (0.93 g/L) concentration, affected an increase of X(max) to 12.38 g/L and lipid a accumulation of 195.77 mg/g dcw. This contributed to a lipid productivity of 173.11 mg/L per day in the course of two-week cultivation.
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Mohd Shamzi
authors.initials: MS
authors.lastname: Mohamed
authors.forename: Joo Shun
authors.initials: JS
authors.lastname: Tan
authors.forename: Rosfarizan
authors.initials: R
authors.lastname: Mohamad
authors.forename: Mohd Noriznan
authors.initials: MN
authors.lastname: Mokhtar
authors.forename: Arbakariya B
authors.initials: AB
authors.lastname: Ariff
mesh_terms: D017756:Aquaculture / Q000379:methods*; D018533:Biomass; D018929:Cell Culture Techniques; D003470:Culture Media / Q000737:chemistry; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D050356:Lipid Metabolism; D058086:Microalgae / Q000254:growth & development / Q000378:metabolism*; D008954:Models, Biological; D016571:Neural Networks, Computer; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism; D012044:Regression Analysis; D015003:Yeasts / Q000378:metabolism
chemical_list: D003470:Culture Media; D009566:Nitrates; C031618:sodium nitrate; D005947:Glucose